Understanding the neural regulation of behavioral arousal and motor facilitation is important to understanding the normal control of sleep- wake regulation and control of motor output, as well as elucidating the basis of such clinically relevant conditions such as insomnia, excessive day time sleepiness, rapid-eye movement behavior disorder and narcolepsy. Consequently, the long-term objective of this research program is to understand the role of the posterior hypothalamus in the control of sleep and arousal. The experiments included in the proposal are designed to determine which neurotransmitter systems are involved in posterior hypothalamic regulation of both cortical and behavioral (motor) arousal. They are designed to test the following hypotheses. 1) The cortical desynchrony and behavioral activation associated with electrical microstimulation of the posterior hypothalamus is due to activation of cell bodies and not fibers of passage. 2) Glutamate release into the posterior hypothalamus stimulates both cortical and behavioral components of arousal. 3) Histamine release into the posterior hypothalamus stimulates both critical and behavioral components of arousal. A secondary objective of this proposal is to introduce students to biomedical research. Consequently, the experiments have been designed to allow substantial student involvement. The research proposed will introduce students to the clinically important field of sleep research, as well as basic neurobiological techniques. The techniques and skills the students acquire will provide a sound base for and stimulate interest in more advanced training in the biomedical sciences.